Pharmacology Flashcards
How do barbiturates work as an antiepiletic?
They bind to GABA receptor chloride channels causing them to stay open longer to increase chloride influx and so hyperpolarisation causing inhibition of the impulses.
How does bromide work as an antiepiletic?
It can act as chloride at the GABA receptor chloride channel causing an increase in GABAergic transmission increasing hyperpolarization
What are the three ways by which anticonvulsants can work?
- Altering membrane properties, primarily sodum channels
- Decreasing excitement, primarily the glutamate system
- Increasing inhibitory action, primarily GABA
State the main types of anticonvulsants (4)
- Barbituates
- benzodiazepines
- Bromide
- imepiton
Give an example of a BDZ and a barbiturate
- diazepam
- phenobarbital
How does imepitoin work as an anticonvulsant?
It is a partial agonist at the GABA-A receptors, they increase inhibitory GABAergic transmission as BDZ
How does BDZ work as an anticonvulsant? (3)
- It binds to GABA receptor chloride channels increasing the affinity of GABA for the receptor
- Overall increases the frequency of channel opening
- increase chloride influx and so hyperpolarisation causing inhibition of the impulses
What is the one difference by which barbiturates and BDZs work?
Barbiturates increases the duration of channel opening whereas BDZs increase frequency of channel opening.
What is an anxiolytic drug?
A drug used to treat anxiety
State 5 classes of anxiolytic drug
- BDZs
- Trycyclic antidepressents
- Selective serotonin reuptake inhibitors
- monoamine oxidase inhibitors
- azapirones
What class of drugs can be used to treat cognitive dysfunction and which one is licensed?
Monamine oxidase inhibitors, selegine
How do MAO inhibitors work?
- inhibit monamine oxidase, an enzyme that breaks down dopamine, serotonin, and norepinephrine.
- So they stay in the synaptic cleft for longer and continue to stimulate nerve impulses.
What is the overall beneficial effect of MAOIs for cognitive function?
Increases the amount of dopamine in the brain.
How do TSAs work?
Blocks the reuptake of noradrenaline and serotonin and so enhances their effects
How do SSRIs work?
Block the reuptake of serotonin leading to adaptive change in pre/post synaptic receptors
What are the adverse effects of BDZs? (4)
- memory impairment
- sedation
- ataxia
- increased appetite
What are the adverse effects of TSA? (4)
- sedation
- vomiting
- mydriasis
- urinary retention
What are the adverse effects of SSRI? (4)
- nausea
- diarrhoea
- anorexia
- appetite suppression
What are the adverse effects of MAOIs? (2)
- raises blood pressure when taken with antidepressants
- depression
What is the ARAS? (3)
- The ascending reticular activating system is a series of connected nuclei in the brain
- regulates sleep-wake transitions and wakefulness
- And relays impulses to higher centres
Name three drugs that inhibit cholinergic transmission
- Vesamicol
- Hemicolinium
- Clostridium botulinum
How does vemasicol inhibit cholinergic transmission?
inhibits ACh uptake into vesicles
How does hemicholinium inhibit cholinergic transmission?
Inhibits uptake of chlorine uptake through transporters so ACh cannot be synsthesised
How does clostridium botulinum work?
Stops vesicles fusing with the presynaptic membrane
